The other day I was faced with having to photograph a painting that was mounted on a frame very close to a building. I arranged for the artist (Johnny Meah) to call me when the sun covered the entire canvas. When I arrived I realized that my 21mm lens would not be wide enough to stand with my back against the wall of the building and get the entire painting in the frame. I went to plan B which was to stand off to the side and photograph from an angle.
I wasn’t too happy with the result, but the artist seemed pleased since it was the best photo he had been able to get so far. The painting had to be taken down and shipped out that afternoon. I kept thinking that somehow I could have done better. I just kept thinking about it.
I remembered that back when I had a darkroom, I was able to tilt the enlarging easel a bit to correct for distortions. Some enlargers have lens swing capability which helps, but distortion correction capability is still quite minor. If you went too far, you would exceed the depth of field capability of the enlarging lens resulting in a portion of the print being out of focus.
Then a lightbulb came on in my head. Photoshop had a distortion capability in the transform menu. If I could distort this image in the exact reverse that the painting was distorted, perhaps I could un-distort the painting.
Sure enough, it worked perfectly! The negative was high quality and my Nikon CoolScan V scanner set to highest resolution scan gave me a lot of extra pixels. There was a loss of data but it was within the range to permit me to obtain a high quality image in the end. The artist was very pleased at the final result. We both had a good laugh when we realized that the frame strut on the left could have been removed for the purpose of making the photograph. Somehow it did not occur to either of us to do it. I show the un-cropped image at right to demonstrate the amount of distortion required to un-distort the actual painting. I then tightly cropped the painting to match the edge of the canvas.
By the way, this banner will be used in the upcoming film “Passion Play” starring Megan Fox, Mickey Rourke and Bill Murray.
Photoshop is really a giant leap forward from the days of enlarger, chemicals, trays and darkroom. I don’t think I could have ever obtained such an extreme perspective correction by simply tilting the enlarging easel. I still like the “look” of film and I miss using Panatomic-X film. (See the page on my blog 6 wellesley west for more about Panatomic-X.) Technology marches on and in time there may come a digital camera that can match or exceed film… even Panatomic-X.